|Female zygiella x-notata aka Dark-legs|
They are a couple, probably zygiella x-notata, sharing a web. Light-legs, the male, got there first, but Dark-legs, the female, wanted, and got, the fly. I have been poking around a bit, but I can't tell which of them likely built the web.
As far as I can tell, the couple got through yesterday's torrential downpour all right. At least, there are still spider legs visible behind the trellis near the edge of the web.
(1) Yes, I could have waited until after they'd replied to my ID requests, but I was too excited and interested.